A medical laboratory professional is reviewing the daily quality control data for a glucose assay on a Levey-Jennings chart. The last five consecutive control values have all plotted on the same side of the mean, but are still within ±2 standard deviations. Which of the following does this pattern most likely indicate?
-
A
A random error has occurred.
-
B
The control material is contaminated.
-
C
A systematic error is developing.
-
D
The instrument is functioning optimally.